LeetCode Topics

Array

Problem Name	Difficulty
0001-two-sum	Easy
0014-longest-common-prefix	Easy
0016-3sum-closest	Medium
0034-find-first-and-last-position-of-element-in-sorted-array	Medium
0051-n-queens	Hard
0054-spiral-matrix	Medium
0119-pascals-triangle-ii	Easy
0448-find-all-numbers-disappeared-in-an-array
0485-max-consecutive-ones
0643-maximum-average-subarray-i
0825-friends-of-appropriate-ages	Medium
0977-squares-of-a-sorted-array	Easy
1019-squares-of-a-sorted-array
1438-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit	Medium

Hash Table

Problem Name	Difficulty
0001-two-sum	Easy
0012-integer-to-roman	Medium
0017-letter-combinations-of-a-phone-number	Medium
0242-valid-anagram	Easy
0448-find-all-numbers-disappeared-in-an-array

Sliding Window

Problem Name	Difficulty
0643-maximum-average-subarray-i
1438-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit	Medium
1567-maximum-number-of-vowels-in-a-substring-of-given-length

String

Problem Name	Difficulty
0012-integer-to-roman	Medium
0014-longest-common-prefix	Easy
0017-letter-combinations-of-a-phone-number	Medium
0022-generate-parentheses	Medium
0093-restore-ip-addresses	Medium
0242-valid-anagram	Easy
1567-maximum-number-of-vowels-in-a-substring-of-given-length

Two Pointers

Problem Name	Difficulty
0016-3sum-closest	Medium
0825-friends-of-appropriate-ages	Medium
0977-squares-of-a-sorted-array	Easy
1019-squares-of-a-sorted-array

Sorting

Problem Name	Difficulty
0016-3sum-closest	Medium
0242-valid-anagram	Easy
0825-friends-of-appropriate-ages	Medium
0977-squares-of-a-sorted-array	Easy
1019-squares-of-a-sorted-array

Tree

Problem Name	Difficulty
0094-binary-tree-inorder-traversal	Easy
0100-same-tree	Easy
0101-symmetric-tree	Easy
0104-maximum-depth-of-binary-tree	Easy

Depth-First Search

Problem Name	Difficulty
0094-binary-tree-inorder-traversal	Easy
0100-same-tree	Easy
0101-symmetric-tree	Easy
0104-maximum-depth-of-binary-tree	Easy

Breadth-First Search

Problem Name	Difficulty
0100-same-tree	Easy
0101-symmetric-tree	Easy
0104-maximum-depth-of-binary-tree	Easy

Binary Tree

Problem Name	Difficulty
0094-binary-tree-inorder-traversal	Easy
0100-same-tree	Easy
0101-symmetric-tree	Easy
0104-maximum-depth-of-binary-tree	Easy

Matrix

Problem Name	Difficulty
0054-spiral-matrix	Medium

Simulation

Problem Name	Difficulty
0054-spiral-matrix	Medium

Math

Problem Name	Difficulty
0002-add-two-numbers	Medium
0012-integer-to-roman	Medium
0050-powx-n	Medium
0069-sqrtx	Easy
0343-integer-break	Medium

Recursion

Problem Name	Difficulty
0002-add-two-numbers	Medium
0050-powx-n	Medium

Binary Search

Problem Name	Difficulty
0034-find-first-and-last-position-of-element-in-sorted-array	Medium
0069-sqrtx	Easy
0825-friends-of-appropriate-ages	Medium

Dynamic Programming

Problem Name	Difficulty
0022-generate-parentheses	Medium
0119-pascals-triangle-ii	Easy
0343-integer-break	Medium

Trie

Problem Name	Difficulty
0014-longest-common-prefix	Easy

Backtracking

Problem Name	Difficulty
0017-letter-combinations-of-a-phone-number	Medium
0022-generate-parentheses	Medium
0051-n-queens	Hard
0093-restore-ip-addresses	Medium

Stack

Problem Name	Difficulty
0094-binary-tree-inorder-traversal	Easy

Linked List

Problem Name	Difficulty
0002-add-two-numbers	Medium

Queue

Problem Name	Difficulty
1438-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit	Medium

Heap (Priority Queue)

Problem Name	Difficulty
1438-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit	Medium

Ordered Set

Problem Name	Difficulty
1438-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit	Medium

Monotonic Queue

Problem Name	Difficulty
1438-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit	Medium